ABSTRACT
This chapter will provide you with an introduction to the essential electrical theory that underpins the rest of this book. It has been designed to help fi ll any gaps in your knowledge and bring you quickly up to speed. You will fi nd this chapter particularly useful if you have not previously studied electrical principles. However, if you are in any doubt as to whether or not you should work through this chapter you can always turn to Section 1.9 on page 33 and see how you get on with the multiple choice questions at the end of this chapter.
